Answer:
Explanation:
The rule governing the number of magazines sold varies directly with the constant of proportion 10:
10 times the number of students comes out to 100: 10(10) = 100
25 times the number of students comes out to 250: 10(25) = 250
and so on.
In summary: the number of magazines sold is y = 10x, where x is the number of students involved.